Sound box of gramophones and like sound-reproducing machines



A. L. COLLINS July 22, 1930.

SOUND BOX OF GRAIOPHONES AND LIKE SOUND REPRODUCING MACHINE$ Filed Jan. 18, 1929 1 6 A 7' ale 1 174 C'azz/m A Patented July 22, 1930 UNITED STATES AUBREY nawmmcn COLLINS, or LONDON, ENGLAND, ASSIGNOR 'ro LIMIT nnemnnn- ING oomramr LIMITED, or LONDON, ENGLAND, A conronarron or GREAT BRITAIN SOUND BOX 0] GRAMOPHONES AND LIKE SQI TND-REPRODUCING MACHINE Application filed January 18, 1929, Serial No. 338,877, and in Great Britain February 21, 19281 This invention relates to sound boxes of gramophones and like sound reproducing machines.

According to the present invention I provide a sound box for gramophones and like sound reproducing machines in which the stylus bar is connected to the diaphragm thereof at a point which is more remote from the fulcrum pivots of the stylus bar than is the axis or centre of the diaphragm.

According to a further feature of the invention I provide a sound box in which the outlet of the sound box to which the tone arm is attached is arranged co-axially with respect to the diaphragm and out of centre with respect to the point at which the stylus bar is connected to the diaphragm or vice-versa.

According to a still further feature of the invention I provide a sound box in which the diaphragm is of corrugated or undulatory formation surrounding the point at which the stylus bar is connected to the diaphragm.

In order that the present invention may be clearly understood and more readil carried into effect, it is hereinafter descri ed with reference to the accompanying drawings in which Figure 1 is a front side elevation of a gramophone sound box in accordance with the present invention;

Figure 2 is a sectional side elevation thereof; and

Figure 3 is a rear elevation thereof.

As shown and in carrying the present invention into effect the stylus bar 10 is connected to the diaphra 11 of the sound box at a point 12 dispose eccentricallg with respect to the axis or centre 13 of the ia hragm 11. The stylus bar 10 may be pivota ly connected to the sound box casing 14 in any appropriate manner as by meansof the pivot screws 15 and is attached to the diaphragm so that the point of connection 12 therewith is more remote from the fulcrum pivots 15 of the stylus bar 10 than the axis 13 of the diaphragm 11 from the said pivots 15. This arrangement gives increased length to the stylus bar. The outlet 16 of the sound box to which the tone arm (not shown) is attached may be arranged as shown, co-axially with respect totheaxis 13 of the diaphragm 11 or if preferred it may be disposed co-axially with respect to the point 12 at which the stylus bar 10 is connected to the diaphragm. The diaphragm 11 which may be interposed between the usual yieldable rings 17 within the casing 14 of the sound box may be corrugated or of undulatory form in cross-section at the part 18 thereof surrounding the point 12 at which the stylus bar 10 is connected to the diaphragm 11 for the purposeof obtaining a more effective eddying of the sound waves, such undulations 18 being afforded by alternate concentric grooves and projections radiating from a centre coincident with the point 12 at which the stylus bar 10 is connected to the diaphra m 11, whereby the central part of the diap ragm tends to remain substantially parallel to the back and front of the sound box during its oscillatory movement.

At its back portion the casing 14 is recessed as shown at 19 to form a seatin for a rubber or like flanged ring 20 which orms a socket to engage the end of the tone arm, the ring 20 being held in place by means of an annular metal ring 21 and fixing screws 22. At its front the diaphragm 11 and stylus bar 10 is protected by means of a fenestrated or openwork cover plate 23 which is held in place by fixing screws 24 engaging the casing of the sound box.

1. A sound box for gramophones and like sound reproducing machines in which the stylus bar is connected to the diaphragm thereof at a point which is more remote from the fulcrum pivots of the stylus bar than is the axis or centre of the diaphragm.

2. A sound box according to claim 1, in which the outlet of the sound box to which the tone arm is attached is arranged co-axially with respect to the diapragm and out of centre with respect to the point at which the stylusbar is connected to the diaphragm.

3. A diaphragm for gramophone and the like sound boxes, formed with a plurality of circular corrugations or undulations arranged eccentrically of the center of the diaphragm, and a stylus bar connected to the III diaphragm at a point centrally of such corrugat-ions.

4. A sound box for gramophones and the like, having a stylus bar connection eccentrically disposed with respect to the axis of the diaphragm, and a stylus bar terminally secured to such connection and pivotally supported beyond the diaphragm, the point of connection of the stylus bar to the dia hragm defining a distance in excess of that etween the pivotal support of the stylus bar and the center of the diaphragm, the diaphragm having a series of corrugations concentric with the point of connection of the stylus with the diaphragm.

AUBREY LAWRENCE COLLINS. 

